Extruding multiple edges simultaneously but separately
The best I could come up with is:

(i) Extrude and tapping z to constrain to the z-axis.  (The constraint keys combined with Transformation Orientations are well put together in Blender so you should check into those as well.)  

(ii) For some reason, using Rip v doesn't work for the entire edge loop so I separated the Vertices a few edges at a time.

(iii)  Scaling by normals separates them without distortion Alt+s so once the scaling was finished I used regular scaling to bring the edges back down.(again, constrained to 'z')